Toshiba TV29C90 problem; Image fades to black...

You still need to check the load on the 200v line after making sure the
diode is in fact good.
Given the history of the arcing I am still betting on a shorted video
output on the red crt.
 
By checking the load, do you mean once I replace the resistor check to
make sure the voltage is +200Vdc ?
Or the resistance measurement ?
 
After verifying that the diode is in fact good.
You can either:
A. Replace the resistor and wait for the magic smoke to come out of it,
with a chance of causing other damage.
B. Before replacing the resistor. Measure the resistance on the 200v
line to ground where it goes to the crt pcbs and make sure you are not
reading some really low resistance. The resistance reading should be
way more than the 2watt or so resistor on the collector of the video
output. That resistor is usually around 1.5K - 2K as a rough guide.
If one of the transistors is shorted you will have a reading roughly
equal to the value of that resistor. Take a look at the schematic on
the crt pcbs.

For your information, the so called troubleshooting guide is done by
engineers who are guessing as to the typical failures, not technicians
with real world failure experience in the set. Yes it is possible that
the diode or resistor is the only problem, but given the history of the
set you need to confirm the other possibility.
 
I am trying to make sure I understand you correctly, after all I am
still learning :)
I had disconnected the 200Vdc on each of the crt pcb's previously. On
each of the crt pcb's the resistance between the +200Vdc in on the crt
and the GND pin was infinate on each of the crt boards.

I also measured the resistance between 200Vdc and GND when it was
attached separatly to each crt and then read a resistance of about
234k.

Is the first resistance measurement what I am looking for or am I
checking the wrong spot ?

This is really appreciated by the way, I have learnt more in the last
month about electronics then I have in years.
 
Those are high enough readings to go ahead and replace the resistor.
What you didn't want was a reading of say around 2K.

Make sure the diode measures correctly first though. Had the high
voltage arc hit the 200v line, it may have damaged the diode along with
the resistor. Easy to check with a multimeter diode check function in
circuit.

You probably need to make sure you get the correct type of resistor as
the wrong type could possibly cause a fire if it fails in a short
circuit condition of the diode. The diode is also likely a high speed
switching type if it needs replaced. Just look at the service manual
for the exact part designations.
 
Hi,

More progress....

I now have established that there is one way of connecting the cables
which enables me to see freeview and to record and play discs on my dvd
recorder.
This is as follows:

1. Main aerial into Freeviw antenna in
2. RF cable from TV out on Freeview to Antenna in on DVDR
3. RF cable from TV out on DVDR to TV VCR combo.
4. Scart from VCR on Freeviw to Scart IN on DVDR
5. Scart from OUT on DVDR to TV VCR combo

This would be fantastic except for the exceptionally poor picture. I've
tried to tune the TV, Freeview and the DVDR but to no success. Boo hoo!
;o)


--
floss
 
Hi,

More progress....

I now have established that there is one way of connecting the cables
which enables me to see freeview and to record and play discs on my dvd
recorder.
This is as follows:

1. Main aerial into Freeviw antenna in
2. RF cable from TV out on Freeview to Antenna in on DVDR
3. RF cable from TV out on DVDR to antenna in on TV VCR combo.
4. Scart from VCR on Freeviw to Scart IN on DVDR
5. Scart from OUT on DVDR to TV VCR combo

This would be fantastic except for the exceptionally poor picture. I've
tried to tune the TV, Freeview and the DVDR but to no success. Boo hoo!
;o)

Does anyone know if my problem would be solved by buying a newer TV...
?? If I had a TV that had two scart sockets (meaning I could plug in
the freeview AND the DVDR), would this help?

Any advice much appreciated.

Floss


--
floss
 
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com>
wrote:

Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.
Click to expand...
---
What's your point?

Are you saying that you have spectrum analyzers (which you say are
garbage) that you want to get rid of, or are you saying that you'd
like someone to dump a spectrum analyzer into your garbage can?

--
John Fields
Professional Circuit Designer
 
On Mon, 09 Jan 2006 00:01:54 -0600, clifto <clifto@clifto.com>
wrote:

maxfoo wrote:
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.

Will it do phase noise measurements for me?

Only if someone sends me the right kind of garbage.
Click to expand...
---
With all due respect, and being as polite as I can, I must say that
after reading your four posts to sci.electronics.design, I get the
feeling that you don't know what you're talking about.

Prove me wrong?

--
John Fields
Professional Circuit Designer
 
John Fields wrote:
On Mon, 09 Jan 2006 00:01:54 -0600, clifto <clifto@clifto.com
wrote:

maxfoo wrote:
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.
???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.
No, they're garbage.

I have a really nice garbage can in case anyone wants.
Will it do phase noise measurements for me?
Only if someone sends me the right kind of garbage.

---
With all due respect, and being as polite as I can, I must say that
after reading your four posts to sci.electronics.design, I get the
feeling that you don't know what you're talking about.

Prove me wrong?
Click to expand...
Some postings on this newsgroup aren't meant for the humor impaired.

Do you really want this "joke" explained?

-Chuck
 
On Sun, 15 Jan 2006 18:21:02 -0500, Chuck Harris
<cf-NO-SPAM-harris@erols.com> wrote:

John Fields wrote:
On Mon, 09 Jan 2006 00:01:54 -0600, clifto <clifto@clifto.com
wrote:

maxfoo wrote:
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.
???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.
No, they're garbage.

I have a really nice garbage can in case anyone wants.
Will it do phase noise measurements for me?
Only if someone sends me the right kind of garbage.

---
With all due respect, and being as polite as I can, I must say that
after reading your four posts to sci.electronics.design, I get the
feeling that you don't know what you're talking about.

Prove me wrong?

Some postings on this newsgroup aren't meant for the humor impaired.

Do you really want this "joke" explained?
Click to expand...
---
Sure.

Go for it.

--
John Fields
Professional Circuit Designer
 
John Fields wrote:

#0 >>>>>>> Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.
#1 >>>>>> No, they're garbage.

#2 >>>>>> I have a really nice garbage can in case anyone wants.
Click to expand...
#3 >>>>> Will it do phase noise measurements for me?
#2 >>>> Only if someone sends me the right kind of garbage.

....
Some postings on this newsgroup aren't meant for the humor impaired.

Do you really want this "joke" explained?

---
Sure.

Go for it.
Click to expand...
The OP posted that he was thinking of getting rid of his
spectrum analyzer, and was wondering if there was some inherent
use that, as a hobbyist, he might of missed.

#0 was a reasonable response to this request for information.

#1 says they are garbage in faint hopes of convincing the OP that
he should get rid of his spectrum analyzer.

#2 echoes #1, and offers up a garbage can for the OP to put his
spectrum analyzer in.

#3 plays the straight man, and wonders if the "really nice garbage can"
can do phase noise measurements.

#2 plays the comic, and implies that if someone puts a
spectrum analyzer (the right kind of garbage) in his garbage can,
then his garbage can will be able to make phase noise measurements.

Bah duh BUMP! (the sound of the ever present drum in the club band)

I didn't think that you would be so humor impaired that you would
miss the meaning of this simple thread. This is just plain old
ham banter the likes of which is heard daily on the informal nets
on the ham bands, or at hamfests everywhere.

-Chuck
 
Chuck Harris wrote:

I didn't think that you would be so humor impaired that you would
miss the meaning of this simple thread. This is just plain old
ham banter the likes of which is heard daily on the informal nets
on the ham bands, or at hamfests everywhere.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Click to expand...

Don't be too hard on the guy. This kind of humor depends heavily on
voice inflection, something not easily done on Usenet.

Bill, W6WRT
 
Salvatore Wrote:
Hi,

Anyone have any other source for Answering machine/phono belts other
than
kenselectronics site??

Thanks
Click to expand...
Yes. Checkout the following:

http://tigerdirect.partsearch.com

I just purchased belts for my Panasonic KX-2740 which has been going
strong for years. This is my second belt change. Square belts were
$1.45 each however shipping, with the new UPS rates, was about $7.50.

Jason Palmer


--
jasonpalmer
 
On Sun, 15 Jan 2006 18:53:15 -0600, John Fields wrote:

On Sun, 15 Jan 2006 18:21:02 -0500, Chuck Harris
cf-NO-SPAM-harris@erols.com> wrote:


John Fields wrote:
On Mon, 09 Jan 2006 00:01:54 -0600, clifto <clifto@clifto.com
wrote:

maxfoo wrote:
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com> wrote:
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.
???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.
No, they're garbage.

I have a really nice garbage can in case anyone wants.
Will it do phase noise measurements for me?
Only if someone sends me the right kind of garbage.

---
With all due respect, and being as polite as I can, I must say that
after reading your four posts to sci.electronics.design, I get the
feeling that you don't know what you're talking about.

Prove me wrong?

Some postings on this newsgroup aren't meant for the humor impaired.

Do you really want this "joke" explained?

---
Sure.

Go for it.
Click to expand...
Geez, John, even _I_ got it! Guy A says, "My scope is garbage." Guy
B says, "I have a nice garbage can", which implies (at least it did
to me), "Go ahead and throw it this way!"

Admittedly, not the world's greatest humour, but I don't think it was
meant to be taken so seriously as to spoil anybody's day. ;-)

Cheers!
Rich
 
On Sun, 15 Jan 2006 16:30:09 -0600, John Fields wrote:
On Sun, 08 Jan 2006 17:02:05 -0600, clifto <clifto@clifto.com
Paul Burridge wrote:
xray <notreally@hotmail.invalid> wrote:
No, Spectum Analysers are useless for anyone outside the government or
RF extremists.

???
Er, they're extremely useful pieces of test gear for anyone involved
in RF., even hobbyists.

No, they're garbage.

I have a really nice garbage can in case anyone wants.

What's your point?

Are you saying that you have spectrum analyzers (which you say are
garbage) that you want to get rid of, or are you saying that you'd
like someone to dump a spectrum analyzer into your garbage can?
Click to expand...
It looks like xray said, "Spectrum analyzers are OK", then Paul Burridge
said, "No, they're garbage", then clifto said, "I have a nice garbage
can" as in "toss it this way! <leer, snort>" ;-)

At least, thanks for maintaining attribution here so I could 'splain
it to you. :p

Cheers!
Rich
 
Thanks a bunch everyone, I replaced the resistor and tested the diode.
The diode was good.
Now that the resistor is replaced and I cleaned up that node and put
some new dielectric silicone on it. It works great and no more arcing.
 
floss wrote:
Hi,

More progress....

I now have established that there is one way of connecting the cables
which enables me to see freeview and to record and play discs on my dvd
recorder.
This is as follows:

1. Main aerial into Freeviw antenna in
2. RF cable from TV out on Freeview to Antenna in on DVDR
3. RF cable from TV out on DVDR to antenna in on TV VCR combo.
4. Scart from VCR on Freeviw to Scart IN on DVDR
5. Scart from OUT on DVDR to TV VCR combo

This would be fantastic except for the exceptionally poor picture. I've
tried to tune the TV, Freeview and the DVDR but to no success. Boo hoo!
;o)

Does anyone know if my problem would be solved by buying a newer TV...
?? If I had a TV that had two scart sockets (meaning I could plug in
the freeview AND the DVDR), would this help?
Click to expand...
is the picture poor on:
a) the dvd
b) the freeview channels
c) the vcr
d) normal terrestrial channels??

....give me a grading for each of the above and we can narrow down the
problem.

-B.
 
b Wrote:
Hi,

More progress....

I now have established that there is one way of connecting the cables
which enables me to see freeview and to record and play discs on my
dvd
recorder.
This is as follows:

1. Main aerial into Freeviw antenna in
2. RF cable from TV out on Freeview to Antenna in on DVDR
3. RF cable from TV out on DVDR to antenna in on TV VCR combo.
4. Scart from VCR on Freeviw to Scart IN on DVDR
5. Scart from OUT on DVDR to TV VCR combo

This would be fantastic except for the exceptionally poor picture.
I've
tried to tune the TV, Freeview and the DVDR but to no success. Boo
hoo!
;o)

B Wrote:
is the picture poor on:
a) the dvd
b) the freeview channels
c) the vcr
d) normal terrestrial channels??

....give me a grading for each of the above and we can narrow down the
problem.

-B.
Click to expand...
Hi B,

Thanks for replying!

Well, with the cables arranged as I said, the picture is exceptionally
poor on freeview. Normal terrestrial channels are ok, not great but
watchable. When playing a pre-recodrded disc in the DVDR, the picture
is perfect. I'm not sure about the VCR because at the moment its not
working properly anyway. When I play videos the picture 'slips'. Thats
why I was considering a new TV. Its only just occurred to me, but might
this be why I cant get things to work?

Looking forward to your reply.

Floss.


--
floss
 
Chuck Harris wrote:
I didn't think that you would be so humor impaired that you would
miss the meaning of this simple thread. This is just plain old
ham banter the likes of which is heard daily on the informal nets
on the ham bands, or at hamfests everywhere.
Click to expand...
And occasionally on Usenet. :)

--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.
 
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